Travel lock



Qec. 3, 1946. Q. BERG TRAVEL LOCK Filed May 17, I945 FIG! 4 INVENTOR Quantin B213 BY ATTORNEYS Patented Dec. 3, 1946 (Granted under the act of March 3, 1883, as

amended April 30, 1928; 3'70 0.. G. 757) 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention pertains to a novel travel lock for a gun having a delicate elevating mechanism which is subject to shocks and stresses such as those transmitted from a moving vehicle on which the gun is mounted. The invention is also useful with a stationary gun for protecting the elevating mechanism from various vibrations.

In considering a gun in a tank as an example, it is obvious that road shocks will be transmitted to the accurately machined elevating mechanism unless some preventive means is provided. This means ordinarily consists of a lock designed to fix the gun relatively to the tank. In order to protect the elevating mechanism, the lock must be constructed even more accurately than the mechanism, for otherwise it will permit movement of the gun relative to the tank resulting in movement and wear in the delicate elevating mechanism. The provision of a simple and easily operated lock meeting this requirement has not hitherto been successfully accomplished.

The present invention attacks the problem from a different direction. An extremely simple and rather coarse lock or latch for the gun is employed, merely for the purpose of holding the mechanism against vibration relative to the tank in large amplitudes. The elevating mechanism includes a vertical suspended shaft with a traveling member thereon and means for transmitting the motion of the traveling member to the gun. I have found that a resilient suspension for this shaft, in combination with the coarse latch, effectively absorbs shocks transmitted through the latch and thus protects the more delicate adjusting mechanism. The suspension is in the form of supported resilient bushings receiving a cross pin passed through the upper end of the shaft. A further advantage of the invention is that the bushings are inexpensive and can easily be replaced if they become worn or otherwise defective.

The invention is fully disclosed by way of example in the following description and in the accompanying drawing in which:

Figure 1 is a detail elevation within a tank, showing a portion of the gun in elevation;

Figure 2 is a vertical section, partly in elevation, of the gun elevating mechanism;

Figure 3 is a side elevation of the latch;

Figure 4 is an elevation at right angles to Figure 3;

Figure 5 is a detail section showing the detent on the locking pin.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

In Figure 1 the numeral l designates an overhead support from which the gun elevating mechanism is suspended. The support may be stationary, rotary, mobile or both mobile and rotary such as the turret of a tank or tank destroyer. A gun 2 is mounted on a trunnion 3 in the structure 4 beneath the support I in the usual manner. A mechanism for elevating the gun is shown and described in detail in, one of my copending applications, serial No. 482,863, filed April 13, 1943, now Patent No. 2,368,191, issued January 30, 1945. This mechanism includes a suspended threaded shaft, and the suspension comprises a plate 5 fastened to the support 1 and formed with a pair of depending apertured ears 6. The suspended rod 1 is drilled transversely at its upper end as indicated by the numeral 8 to receive a tightly fitted bolt or pin 9 mounted in the ears 6. A resilient bushing Ill lines each of the ears and fits on the enclosed part of the pin 9 to provide a resilient or cushioned suspension for the rod I.

The shaft is threaded at l I a considerable distance upward from its lower end, and on the threads is mounted a travelling member shown as a movable nut l2. The nut supports a housing l3 by appropriate means and the nut is rotated by a handle IE to move along the rod 1 and carry the housing with it, as shown and described in the aforementioned copending application. The housing 13 is bolted at Ii to the gun cradle l5, whereby movement of the nut 52 and housing [3 alters the elevation of the gun.

As already indicated, the resilient suspension for the shaft obviates the necessity for a finely machined latch or lock. In this case the latch is of a very simple and coarse construction as shown in Figures 1, 3 and 4. To the underside of the support I is secured, as by welding, a strip 20 having ears 2! and 22 formed at its ends. An H-shaped latch 23 is hinged on the ear 22 by a pin 24. The other end of the member 23 is apertured at 25 to register with an ear 26 formed on the cradle l 5. The gun is locked by passing a pin 21 through the alined holes. One end of the pin is formed with a knob 28 and the other exposed end is fitted with a spring-pressed ball detent 29. The pin is thus retained in locking position but can be withdrawn manually by a hard pull on the knob 28. As mentioned above, the latch is of coarse construction and the parts thereof are machined with relatively large tolerances, resulting in case of manufacture. Due to the relatively loose fits between the parts of the latch, the pin 21 is easily inserted through the aligned holes in the member 23 and the ear 26.

When the latch piece 23 is released from the ear 26, it is'swung upward so that its apertured free ends register with the ear 2|, and the pin 21 is inserted in the alined holes. In order that the pin shall not become lost, it may be chained at 30 to the support I.

The gun 2 is delicately balanced on trunnions 3 and, unless locked, would rock relativeto the vehicle in response to road shocks during travel of the carrying vehicle. The tendency of the gun to rock relative to its mounting on the vehicle would exert stresses on,-and in time-cause wear and injure, the delicately machined elevating mechanism. Forthis reason a travel lock is used and, in order to protect the elevating mechanism from transmitted road' shock's, must be even more accurately machined than the mechanism. To provide such a lock thatisreasonably simple in construction and easily operated is'a difficult problem that has notyet been sati sfactorily solved. The travel locks hitherto available have been unsuccessful in use, principally because of the neglect of the men to apply them before traveling, especially in combat.

--'I--he lockdescribedherein, as already pointed -out,-is of exceedingly simple and rathercoarse construction, so that it does notrequire accurate al-inement of the holes in order to be engaged.

The relatively large tolerances in the travel lock permit a small relative movement between the gun and the vehicle, but this is effectively absorbed in'the resilient bushings Hi without injury to the delicate parts of the elevating mecha- -nism. On-the other hand, the bushings are sufficiently st ifi to permit sensitive and accurate elevation control withoutthe feeling of backlash. Even Without the latch in the locked-position on the. gun,'the rotating nut '12 andthe threads I tare cushioned-by the bushings against shock. The bushings may-become worn or compressed in time but they are-inexpensive and easily replaced on withdrawing the ping.

'Although aspecific embodiment of the invention has been illustrated and described, it will be understood that Various alterations in the details of construction may be made without deiparting from the scope of the invention as iridigun in limited amplitudes, with 'respectto said support, said means also including a resilient element, whereby shocks transmitted through said coarse latch piece are effectively absorbed, thus protecting said relatively delicate elevating mechanism.

2. In combination with a gun pivotally mounted on a support subject to vibrations and having a relatively delicate mechanismfor elevating said gun and a, connection between said mechanism and said support, a coarse latch piece connecting said gun to said support, said latch piece being constructed and arranged to prevent vibration'of said gun in large amplitudes, yet to permit vibration of said gun in limited amplitudes, with respect to said support, the said connection comprising a, resilient element between -said "elevating mechanism and said sup- 7 port, WhEIGbY'ShOCkS transmitted through said coarse latch piece are efiectively absorbed, thus protecting said relatively delicate .elevating mechanism.

3.7In. combination with. a gunpivotallymounted on a support subject.to -vibrations..and .hav-

iingca relatively delicatemechanism for elevating said gun and a connection wbetweenlsaid mechanism and. said support, a coarse latchpiece connecting said gun tosaid support, said latch piece being constructed andarrangedtdpre-vent vibration of .said .gun .in large amplitudes, ,yet to permit vibration. of .said gun .in limitedamplitudes, with respect to said support, thewsaid connection comprising-a pair of apertured ears pin passing through the apertures vof said ears and-through the hole in'said-rod and resilient. bushings=in said apertures and surrounding said .pin, whereby shocks transmitted through said coarse latch piece are 1 effectively. absorbed, thusprotecting said relatively delicate elevating mechanism.

In: combination with agun pivotally mountedon-a, support-subject to vibrationsandihaving a relatively delicate mechanism 1 for elevating said gun and a connection between' said naechanismand said support, .a coarse-latch, piece comprising an arm pivoted to said support-and said gun I in 1 large amplitudes, yetoto permit vvibration of said guninlimited .amplitudes,-with respect tozsaidsupport, the said: connection. comprising a pairnoflaperturedears carried by said "support-a rod carriedbysaid mechanism-and having -a, .hole therethrough, a .pin passing through-. the apertures of saidears andthrough the lhole. .in -.saidlrod, -and resilient bushings in said. aperturesand. surrounding said,.pin,- .whereby shocks transmitted .through said .coarselatch piece areeffectively absorbed, thus. protecting said relatively Ldlicate elevating :mechamsm.

-QUENTIN BERG. 

